Firefly Watch: Frequently Asked Questions

Photinus firefly foraging for food © Don Salvatore
© Don Salvatore

Questions about the project? Explore our FAQ! If you don’t find the answer you were looking for, email us.

When should I start collecting firefly data?

The simple answer is just before firefly season starts in your area. If you start observing before fireflies are expected to emerge, then you will be sure to record when they first appear in your habitat.

If I don't have any fireflies in my backyard, should I still report it?

Yes! Please report once a week even if you don't see any fireflies. This is important for two reasons:

  1. It may be that you don't have any species of fireflies active early in the summer, but other fireflies will emerge later in the season. This is valuable information for firefly researchers.
  2. Researchers want to know what affects firefly populations. Why are they common in one area and absent in another? By looking at the data from the habitat sheets for areas with no fireflies, researchers might be able to begin to understand some of the important factors. That is why reporting no fireflies is just as useful as reporting many fireflies.

Collecting data for areas with no fireflies should only take a minute. Walk out into your backyard, look around for 10 seconds to make sure there are no fireflies present, and note the time, clouds, wind, and temperature.

If I don't have any fireflies in my backyard, can I choose another site that does have fireflies?

Yes! Of course it is a lot more fun to monitor a site with fireflies than one without, so feel free to pick a second site. If you can, pick a site close to your home, because it will be easier to get to on a weekly basis. Make sure that you have permission to visit the site. A public site like a school yard or other town property is a good place to choose.

If you do choose a second site, please remember to send in data for your backyard site as well. That information is very important to us.

Is it OK if I can't collect data every week during firefly season?

Yes! Of course, the more data you can collect, the better, but we appreciate any data you can send us. Even if you can only collect data for a few weeks during the summer, it will be very useful for us.

What is the best time to observe fireflies and collect data?

Different types of fireflies become active at different times through the summer. In New England, our earliest flashing fireflies (Pyractomena) fireflies show up in late May to early June; others will appear in June and July.

Different types of fireflies are also active at different times of night. Some begin flashing at dusk and remain active for less than an hour, while others start later and remain active until midnight. One of our early risers reports seeing fireflies at 4 in the morning.

For Firefly Watch, it doesn't matter when you observe and record. In fact, it might be fun to observe at different times of the evening and see if you can notice a difference in the fireflies you see. If you do this, each time should be its own observation entry.

It's early spring and I'm seeing daytime fireflies. Should I count them and enter them as data for my habitat?

No, because daytime fireflies are not part of this project. Please count only the fireflies that you see flashing. This is especially important in helping us determine when fireflies become active in your state. Some daytime fireflies appear much earlier in the season than the flashing fireflies, so entering data for them might skew our estimates of firefly emergence.

I see larval fireflies glowing in my yard. Should I be counting and recording them?

That’s really cool! But, as with the daytime fireflies, this project does not include larvae counts. However, that may make an interesting project for the future!